1. Field
Exemplary embodiments of the present invention relate to a semiconductor design technology, and more particularly, to an integrated circuit for latching an input signal.
2. Description of the Related Art
An integrated circuit for latching an input signal is frequently used in diverse circuits.
FIG. 1 is a circuit diagram illustrating an integrated circuit for latching an input signal according to a prior art.
Referring to FIG. 1, the integrated circuit for latching an input signal IN includes two inverters INV1 and INV2.
An input terminal of the first inverter INV1 and an output terminal of the second inverter INV2 are coupled with each other, and an output terminal of the first inverter INV1 and an input terminal of the second inverter INV2 are coupled with each other. Therefore, logic levels of an input node IN and an output node OUT are in a complementary relationship to each other.
For example, when the input node IN has a logic high level, the output node OUT has a stable logic low level. In contrast, when the input node IN has a logic low level, the output node OUT has a stable logic high level. A latch circuit formed of the inverters INV1 and INV2 has and holds two different stable logic states at the Input node IN and the output node OUT.
Since the latch circuit formed of the inverters INV2 and IN2 is stable, noise has not become a problem.
However, as the latch circuit is exposed to radioactive rays having ionization characteristics, it is influenced by generated electric charges. That is, the radiation of radioactive rays makes the memory state of the latch circuit unstable, and increases the possibility of a malfunction called ‘an inversion of the memory state’.
This phenomenon is referred to as a soft error, which is caused by α-rays emitted, from package materials or wiring materials, among the radioactive rays having ionization characteristics.
Particularly, soft errors occur more easily as power source voltages become lower. For this reason, in recent semiconductor memory devices driven by a low power source, it is important to increase the resistance to soft errors.